Japanese Patent Application Publication No. 2009-275488 discloses a rebar tying tool that ties plural rebars using a wire. The rebar tying tool is provided with a reel supporting mechanism capable of switching between a first state of detachably supporting a reel on which the wire is wound and a second state of undetachably supporting the reel, a wire feeding mechanism that feeds the wire from the reel, an openable cover that partially covers the wire feeding mechanism, a biasing mechanism that applies biasing force to switch the reel supporting mechanism from the second state to the first state, and a lock mechanism that prohibits the reel supporting mechanism to switch from the second state to the first state.